motor vibration

[crowrod]

I have a vibration from my motor between 1-3k rpms, its not real bad but I can fell it thru my seat and floorboards. The carbs have been synced and the valves have been adjusted. any ideas?

[twigg]

Keep it above 3000 rpm. Problem solved

 

All engines vibrate a bit. Sometimes the resonant frequency is irritating, and it can vary from bike to bike.

 

There may or may not be a minor issue causing it, but most likely it's just one of those things.

[MikeWa]

Probably one of the vibration absorbing oil filled motor mount assemblies has lost it's fluid and and oh wait ...never mind.

 

Mike

[dacheedah]

low idle jet plugged on one carb or the coil or spark plug wire or plug itself. let it run for a few minutes and feel the exhaust, they should be about the same. If one is cooler , check for spark. If you have spark that means u have a fuel delivery problem.

[Trader]

somebody has to say it

 

 

SEAFOAM !!!!!

[twigg]

somebody has to say it

 

 

SEAFOAM !!!!!

 

Last time someone invoked "Seafoam", the thread was deleted .... Terrorist!

 

:rotf:

[crowrod]

Sea foam in , every fill up!

[tazmocycle]

who synced the carbs? may need to check it again, you can add a dyna-tech 3000 to it and that may help out as you can set the timing up which helps out on the low end of power band.

[V7Goose]

I suspect you may be riding a Harley... Check the tank badge. ;-)

Goose

 

But in a slightly more serious tone, the idea about the pilot jets is probably right on the money. At those low RPM/slight throttle settings, the pilot jets are still providing at least 50% of the fuel, so one being even partly plugged will cause a significant imbalance in the engine. It is totally different than carb sync problems, but the results are identical. Carb sync does nothing more than measure the throttle opening, and the results will be the same even if there is no fuel getting through at all. The shaking is just caused by one or more cylinders not producing the same power as the others, no matter what the reason.

Edited October 6, 2012 by V7Goose

[bobcat]

who synced the carbs? may need to check it again, you can add a dyna-tech 3000 to it and that may help out as you can set the timing up which helps out on the low end of power band.

 

I agree. I had a vibration on my 1st gen that I would have sworn was in the drive train, like a bad U joint etc..Someone on this forum suggested syncing the carbs and when I did the vibration was gone..

 

I'd at least check the sync if for no other reason than to eliminate that as the potential problem..

[crowrod]

carb sync has already been done. Thanks for all the input and possible answers to my problem,I will try and clean those pilot jets and go from there.